How to Differentiate 720p and 1080p Television Resolution

In this brave new high definition world, the differences in individual resolution can be very confusing. Most high definition shows these days are broadcast in 720p or 1080p. Because of bandwidth issues, 1080p is only available on HD and Blu-Ray DVDs. You can differentiate between the two by understanding a little more about the technology that's involved.

Difficulty: Moderately Challenging

Instructions

Things You'll Need:

• HD television with 1080p capacity
• HD DVD or Blu-Ray DVD
• HD or Blu-Ray DVD player

1. Use a large HD television capable of 1080p resolution, preferably one 50 inches or bigger. The differences between 720p and 1080p are extremely subtle, and some people swear that the variations cannot be discerned by the naked eye. If you are using a smaller television (less than 42 inches), even the closest scrutiny may not produce any noticeable difference.

2. Turn on the HD DVD or Blu-Ray DVD player and insert a disc. Your television or cable box should allow you to move back and forth between its resolution (1080p) and the resolution of an HD broadcast (720p).

3. Sit closer to the TV than is comfortable. While you should not spend extended amounts of time too close to the TV, a brief sitting can help you differentiate the details between 720p and 1080p more succinctly.

4. Focus on the finer details. Rather than looking at large crowd scenes, unfocused shots or scenes with a darkened frame, examine close-ups and elements such as hair, clothing fabric or rippling wheat fields. The contrast in resolution between 720p and 1080p becomes easier to spot that way.

5. Examine diagonal lines in the image, such as people's arms and shoulders leading up to their heads, the slant of light in a darkened room onscreen or angles on buildings past which the camera may be panning. With 720p, you may notice a slight triangulation along the lines (called the "stair-stepping effect,"), while with 1080p you will not.

6. Look for the density of the pixels rather than the sharpness of the image. While both 720p and 1080p have very sharp resolutions, 1080p tends to pack more pixels into its image. Experts call it the "screen door effect" because when standing close enough to 720p, you can actually notice the space between pixels, while in 1080p, you cannot.

Tips & Warnings

• The "p" in 720p and 1080p refers to "progressive," which means a solid line of pixels across the screen. 1080i, on the other hand, means "interlaced," in which the odd pixels are shown on one scan of the screen and the even pixels on the next (the TV screen is scanned 60 times per second). The numbers themselves refer to the number of horizontal pixels the image resolution depicts, which is important when you want to differentiate between formats.